Improving rheological properties of weak wheat flour by treating with binary mixtures of some enzymes

Abstract

The present work was conducted as an attempt to improve rheological properties of weak wheat flour by treating with binary mixtures of some enzymes. To determine the optimum concentration of each enzyme, they were individually added to the flour using different concentrations followed by measuring the extensograph parameters. Optimun concentration were 5, 83.3 and 0.133 unit/100gm of flour for glucose oxidase, peroxidase and transglutaminase, respectively. They gave the highest resistance of extension beside their other positive effects on dough rheology. Xylanase optimum concentration was 13.7 unit/100gm flour which gave the highest dough extensibility.

The addition of glucose oxidase with transglutaminase led to decrease exitensibility and increase resistance, ratio, maximum resistance and extensograph area. Treatment with glucose oxidase and peroxidase had a large effect in raising resistance and decreasing the extensibility as compared to all other binary enzymes treatments. The addition of xylanase to transglutaminase - treated flour led to decrease resistance and increase extensibility of the dough. Resistance/extensibility ratio reached 4.6 B.U./mm which is near to the desirable range of this parameter. Also, the addition of this enzyme caused to decrease resistance of peroxidase - treated flour but without affecting extensibility. The ratio was 4.4 B.U./mm. However, the extensograph area had increased upon this treatment as compared to the individual treatment of each of both enzymes.